Businesses which have adopted wireless Local Area Networks (LAN) transmit data using radio communications. Since this data may be of a proprietary nature, it should be kept secret. One solution is to restrict access within the network.
FIG. 1 illustrates a wireless LAN in which a control module (CM) 10 utilizes RF communications to communicate with user modules (UM) 12 that are each coupled to one or more user devices 14 consisting of a terminal, personal computer, telephone, or other information input/output device. In the illustrative system, the CM 10 is also coupled by a data channel 16 to a data network. The CM 10 controls communications within the illustrated network and passes information from the data network channel 16 to user devices 14 via an associated UM 12. The CM 10 also controls local communications by receiving information from one UM 12 and relaying the information to a different UM 12. The information is conveyed in the form of packets. The network to which the CM 10 is connected may consist of an Ethernet network, a Token Ring network, or any of the other of the well known voice and data networks.
Access to the wireless LAN is controlled by the CM. Each UM has a unique identification number such as, for example, an IEEE address. This information is stored in CM memory. Prior to permitting network access, the CM must verify the ID of each requesting UM. If the UM is registered in CM memory as an authorized user, the CM will provide service. If, however, the UM's identification number is not found, access is denied.
Whenever a UM moves from one geographic area of coverage (cell) to another, its ID must be deleted from the currently servicing CM and presented to the CM which controls communications within the new geographic area. This is currently a manual operation requiring the assistance of a network administrator. While this method is palatable in most single cell installations, it is extremely inefficient when used in a multiple cell (microcell) environment. The typical microcell installation is characterized by multiple users often segregated into distinct user groups covering diverse geographic areas. Quite frequently, the user within these groups desire mobility. This creates a need for a user access methodology which eliminates network administrator intervention and maximizes system flexibility by assuring ease of relocation, while maintaining high levels of security from unauthorized use.